1. Field of the Invention
The present invention relates to a method of manufacturing a flat panel display of a type having a pattern of constituent elements arranged in correspondence with an arrangement of cells in a display region.
2. Description of the Prior Art
In the course of mass production of flat panel displays (FPDs) such as, for example, plasma display panels, liquid crystal display panels and organic electroluminescence display panels, attempts have hitherto been made to minimize indirect materials of a kind utilized solely for the convenience of manufacture thereof. The indirect materials are, when intended products are completed, in most cases disposed of as wastes and, therefore, the need has been well recognized to minimize the indirect materials not only to avoid concomitant increase of the manufacturing cost, but also to avoid environmental contamination.
The Japanese Laid-open Patent Publication No. 11-273557, published in 1999, discloses the use of an ink jetting technique to form electrodes of the plasma display panel. The ink jetting technique in which an electroconductive inking material is jetted towards a substrate so as to depict a pattern of electrodes is considered economically efficient as compared with the photolithographic technique in which portions of a uniform layer of electrode material are removed to leave a pattern of electrodes. Also, as compared with the screen printing technique, the ink jetting technique is considered effective not only in facilitating accurate formation of the pattern of electrodes with high uniformity over the entire surface of a large size screen, but also substantially eliminating the need of replacement of screens, which would otherwise be performed frequently, resulting in reduction in cost and reduction in length of time required to complete the products.
However, the ink jetting technique involves the following problems when the pattern of electrodes for flat panel display is to be formed:                (1) Unless the support surface on which the electrode pattern is desired to be formed has an excellent wettability, the inking material being jetted tends to scatter and/or fluidize.        (2) Microscopic irregularities peculiar to those occurring when liquid droplets are deposited tend to be observed in edges of the electrode pattern.        
As a technique effective to substantially eliminate the above discussed problems and to form a layer of inking material representing the electrode patterns having a smooth contour, the above mentioned patent publication suggests a method of masking, with a photoresist, an area other than the area onto which the inking material is deposited and a method of shaping the pattern edge by the use of exposure and development subsequent to formation of the electrode pattern with a photosensitive inking material.
The Japanese Patent No. 3395841 discloses a method of making a color filter for a liquid crystal display panel, which method includes forming on a substrate a photocatalyst containing layer, of which wettability varies when irradiated with energies, and irradiating the substrate with energies in a predetermined pattern to enhance the wettability of a portion of the photocatalyst containing layer and depositing a colored ink on the wettability enhanced portion of the photocatalyst containing layer. In other words, this Japanese patent discloses enhancement of the wettability of only a portion of the predetermined pattern formed on the support surface.
In the manufacture of the FPDs hitherto practiced, the use of the ink jetting technique is effective to reduce the amount of direct materials used, but a number of indirect materials are needed and/or special materials must be used to render the resultant electrode pattern to be neatly finished. Masking with the photoresist requires a substantial amount of resist materials so that the latter can be deposited on the entire area of the supporting surface, i.e., a substrate and, also, requires complicated process steps. The use of the photosensitive ink would undesirably recede the merit of reduction of the amount of the direct materials used. Yet, even where a film material effective to vary the wettability of the photocatalyst containing layer, discussed above, when irradiated with energies is employed, the film material in a quantity enough to cover the entire surface of the substrate uniformly is needed.